Metals and alloys, especially those employed in high temperature applications, are often susceptible to reaction (e.g., oxidation, corrosion, diffusion by other species, volatilization of constituent species, etc.) with surrounding and/or nearby chemical species. These reactions can negatively impact the chemical properties, the mechanical properties, and/or the performance of the metals and alloys with respect to their particular application. One way to address the problem is to coat the surface of the metals or alloys with a protective material. Many of the processes for applying such coatings require carefully controlled atmospheres and/or special equipment, which can be expensive and inconvenient to establish and maintain. Accordingly, a need exists for improved methods of applying protective coatings to metal and/or alloy substrates.